1. Field of Invention
This invention relates to heat exchangers and constant volume regenerative heat exchangers which are capable of constant flow, in particular.
2. Prior Art
Presently available regenerative heat exchangers typically operate in a counter-flow, approximately constant pressure manner. Approximately constant pressure heating results in an increase in the specific volume which is proportional to the increase of the absolute temperature. The heat exchanger and the downstream vessels must therefor be enlarged to accommodate the increased specific volume. In some applications, such as in Stirling cycle systems, the required constant volume heat transfer is accomplished in a stop-start manner with a heat absorbing matrix in the path between the hotter and cooler chambers. As a result, the rate of heat exchange is very slow as is the rate of power generation. Many processes are enhanced in efficiency if performed at a higher pressure. Current heat exchangers typically add to the temperature of the heated gas but not to the pressure. There are may situations where a gas is required to be at a state of high pressure as well as high temperature. This is now accomplished by separate compression and heating processes. The present invention accomplishes this in one step; by heat exchange at constant specific volume and steady flow such that the heated gas increases in pressure as well as temperature. This is accomplished with only one device rather than two.
Feldkamp, Gr 608167, 17 Jan. 1935, teaches a hot air rotary piston engine with an outer passage surrounding the heated gas. In order to act as an engine the volumes between the vanes must expand as they do. "In front of the exhaust the ring-like space is, from point F onwards, bulged out so that at this point the vanes C can further jut out of the rotor. From this point on the working spaces are extended."
In contrast our heat exchanger is characteristically and essentially a constant volume heat exchanger instead of an expanding space engine.
Thus, in form (constant instead of expanding) and function (heat exchanger instead of engine) our constant volume heat exchanger is neither anticipated nor suggested by Feldkamp.
Schmied, Fr 688,172, teaches "A system for the cooling of the exterior cylinder or stator of a rotary piston compressor." The volumes trapped between the sliding vanes vary with position as necessary and typical of rotary compressors. Our constant volume heat exchanger is neither anticipated nor suggested by any obvious similarity by Schmied's variable volume compressor.